Whole Exome Sequencing: Why It’s Done and Who It’s For

What is Whole Exome Sequencing?

Whole Exome Sequencing (WES) is a state-of-the-art genetic, tehigh-throughput molecular genetic diagnostic technique that enables parallel analysis of over 21,000 human genes within a single test. 

The exome is the complete set of all exons, i.e. all protein-coding regions of DNA. While comprising only 1.5% of the human genome, this coding fraction accounts for up to 85% of clinically actionable genetic variants linked to hereditary pathology. Exome analysis enables the detection of genetic alterations that may underlie rare monogenic diseases.

Whole exome sequencing is particularly valuable in cases with complex or unclear clinical presentations, where standard diagnostic approaches or targeted genetic panels fail to establish a precise diagnosis.

When may the test be recommended?

Whole exome sequencing may be recommended in the following cases:

• suspected hereditary disease;
• presence of multiple or nonspecific symptoms;
• prolonged diagnostic workup with no established cause of the disease;
• suspected rare genetic syndromes;
• positive family history of hereditary disorders;
• when results of previously performed genetic tests have been inconclusive or insufficiently informative;
• to refine the diagnosis and guide further management and follow-up strategy.

Advantages  of  Whole Exome Sequencing at the Center for Pediatric Oncology, Hematology and  Immunology

• Analysis  of  All  Protein-Coding  Genes

Exome sequencing enables simultaneous interrogation of the coding regions of over 21,000 genes, substantially expanding diagnostic capabilities compared to limited targeted gene panels.

• Technologies Ensuring High Accuracy of results

In the molecular genetics research laboratory of the Scientific Department at the Center for Pediatric Oncology, Hematology and Immunology, enrichment technology employing KAPA HyperCap Target Enrichment Probes (Roche) is utilized, which ensures high accuracy and diagnostic informativeness of the analysis.

• Data re-interpretation capability

Scientific data on genetic diseases and associated genes are constantly being updated. The obtained results can be re-analyzed in the future in light of new clinical and scientific data without the need for repeat sequencing.

• Primary data provision

Primary sequencing data in FASTQ format will be made available upon request at no extra charge. This facilitates independent result interpretation or secondary data analysis should the need arise.

How is the Test Performed?

Whole-exome sequencing is performed on peripheral  patien’s blood samples. Following DNA extraction, library construction and enrichment of the coding regions of the genome are carried out, followed by high-throughput sequencing and bioinformatic processing of the raw data.

Variant interpretation is performed in the context of clinical findings, family history, and current international consensus guidelines, thereby increasing the clinical utility of the test.

Why is this Important?

Next-generation sequencing technologies have markedly expanded the scope of genetic diagnostics. Whole exome sequencing enables a reduction in the diagnostic odyssey, enhances diagnostic yield and accuracy, and facilitates a more individualized, patient-centered approach to clinical management.

The utilization of whole exome sequencing is of particular importance in the context of rare and genetically heterogeneous disorders, wherein overlapping clinical phenotypes may arise from diverse underlying genetic defects.

It should be noted that not all identified genetic variants have a definitive clinical interpretation, and certain variants may require additional functional studies or periodic re-evaluation as scientific data accumulate.

Cost of the procedure: 

5200.00 Belarusian rubles

Phone numbers for appointments and detailed information: 

+375 (17) 287-10-80, +375 (29) 373-83-20 (Fee-Based Services Department)

Working hours (Mon–Fri): 08:00 – 15:40

Turnaround time for the study and result interpretation: 

The analysis and interpretation of the obtained results may take approximately 60 business days. The report with the study results will be sent to the customer’s email address.